Plasma torches are commonly used for cutting, welding, or marking metal work pieces. In general, plasma torches employ an electrode to generate an electric arc within the torch. A high-velocity gas is flowed through the torch, and the electric arc ionizes the gas, creating a plasma. The high-velocity stream of ionized gas, or plasma, is delivered through a nozzle of the torch towards the work piece that is to be operated upon. The plasma serves to conduct electricity from the torch to the work piece. In this way, the plasma heats the work piece, melting the metal in the desired location.
Baffles are commonly used in plasma arc torches to control the flow of gases or liquids. Baffles can be used, for example, to throttle the flow and/or to impart swirl to the flow. Swirl-inducing baffles are generally referred to as swirl baffles, or alternatively as diffusers.
A common type of swirl baffle is an annular ring having flow passages extending between the radially inner and outer surfaces of the ring. The passages extend non-radially, i.e., with a tangential component of direction, so that swirl is imparted to the fluid flowing through the passages. Some swirl baffles of this type have a configuration that allows them to be inadvertently installed upside down relative to the proper orientation. When the swirl baffle is incorrectly installed upside down, the swirl direction imparted by the baffle is the opposite of the intended direction. This can cause problems in some cases, such as when a downstream component's design is such that it works properly only when it receives swirl of a particular sense.